Did not visit the community for a long time, but will follow up my experience with Affinity software. Using Mac OS sierra, the bug is fixed now, probably after some update. It used to be happening mostly in a large documents. Right now I dont have any problems or bugs in the Affinity designer, only if I have document 50+ complex layers and A0+ size, it can not be directly exported, but after rasterizing layers with shades and effects export takes some time, and works fine. I think its the problem is that my apple MacBook graphics card is from 2014 and not powerful enough. Overall i use your product since late 2014 am very satisfied, the software works smoothly and can see positive progress. Always happy to recommend your software to my friends and other designers/artists!